Middleware for Web Services (MWS) workshops at IEEE EDOC conferences:
MWS 2008
(!!!NEW!!!)
MWS 2007
MWS 2006
MWS 2005
Also, see Middleware for Service-Oriented Computing (MW4SOC) workshops at ACM/IFIP/USENIX Middleware conferences:
MW4SOC 2008
(!!!NEW!!!)
MW4SOC 2007
MW4SOC 2006